The present invention relates in general to data compression circuits and in particular to a method and apparatus for reducing sequences of data characterizing sampled waveform magnitudes to data pairs indicating the minimum and maximum data in each sequence.
A digital sampling oscilloscope measures the magnitude of a voltage waveform at regular intervals, converts the analog sample voltages to digital data, and then uses the digital data to control a display of the waveform on a screen. Typically such an oscilloscope is capable of displaying a fixed maximum number of sample data points along a portion of the waveform. To increase the portion of the waveform displayed (i.e. "compress" the waveform), the sampling rate is reduced. This results in a loss of waveform display detail since high frequency, high magnitude oscillations between sampling points will be overlooked.
What would be useful would be a method and apparatus for compressing a waveform image without decreasing the sampling rate and without decreasing the ability to detect and indicate high frequency, high magnitude voltage swings.